The semiconductor integrated circuit (IC) industry has experienced rapid growth. Over the course of this growth, functional density of the devices has generally increased while the device feature size or geometry has decreased. This scaling down process generally provides benefits by increasing production efficiency, lowering costs, and/or improving performance. Such scaling down has also increased the complexities of processing and manufacturing ICs and, for these advances to be realized similar developments in IC fabrication are needed.
Likewise, the demand for increased performance and shrinking geometry from ICs has brought the introduction of multi-gate devices. These multi-gate devices include multi-gate fin-type transistors, also referred to as FinFET devices, because the channel is formed on a “fin” that extends from the substrate. FinFET devices may allow for shrinking the gate width of the device while providing a gate on the sides and/or top of the fin including the channel region.
In addition, with the use of high-k dielectric materials in the gate dielectrics of MOS transistors, the convenience provided by using silicon oxide is no longer a big advantage, and hence germanium is reexamined for use in integrated circuits. Recent studies of using germanium in Fin field-effect transistors (FinFETs) have been reported. However, the technology and materials for processing silicon germanium, for example, selecting and controlling the chemicals for processing and depositing silicon germanium, are still being explored.